1. Field
Embodiments of the present invention relate to display devices with touch input devices and, more specifically, systems and methods for reducing display lag between a touch input device and a display device.
2. Related Art
A display panel that incorporates an overlaid touch sensor panel may be referred to as a touchscreen display, and may provide an interaction system for touch-enabled computing devices (such as mobile phones, tablet computers, laptop computers, or desktop computers). In such computing devices, graphics are displayed on the display panel, and a user may interact with these devices by touching the screen (e.g., by using an active stylus, a passive stylus, or a body part such as a finger), thereby providing an intuitive user interface.
In the touchscreen display, the touch system and display system typically operate independently. Touch events detected by the touch sensor panels are typically processed by high level application software running on an application processor (AP) of the device. That is, the touch system includes a touch controller that processes the signals generated by touch sensors, and that outputs data corresponding to the touch events, such as coordinates, to the AP. The AP is generally located externally from the display. The AP processes the touch events, and updates a display composition accordingly to the display driver interface controller (DDIC). The DDIC processes video images from AP, and outputs pixel driving signals to the display panel.
The many processing operations between the touch sensor panel and the AP, as well as the non-deterministic processing time on the AP (including delays due to other computational tasks that are performed by the AP), introduce high levels of latency that reduce responsiveness of the computing device to the user's touch inputs. For example, contemporary smart phone devices may exhibit delays of about 100 milliseconds (i.e., about 6 frames at 60 frames per second) when writing on the screen with either a finger or stylus.
The above information disclosed in this Background section is only to enhance the understanding of the background of the invention, and therefore it may contain information that does not constitute prior art.